Profile of regional fat and fat-free soft tissue accumulation in male athletes.

BACKGROUND: It is unclear whether or not the breakpoint (BP), at which the proportion of each of fat mass (FM) and fat-free soft tissue mass (FFSTM) to body mass (BM) alter, exists in male athletes. We examined the hypothesis that in male athletes, the regional FM and FFSTM-BM relationships have a BP, but the body mass at BP (BMBP) differs among the arms, trunk, and legs. METHODS: By using a dual X-ray absorptiometry, whole-body and regional FMs and FFSTMs in the arms, trunk, and legs were estimated in 198 male athletes (20.8 ± 2.1 years; 1.73 ± 0.07 m; 72.7 ± 14.8 kg). To detect the BP in the relationship between each of FM and FFSTM and BM, a piecewise linear regression analysis was used. If a BP was detected in the corresponding relationship, the significant difference between the regression slopes above and below the BP was examined. RESULTS: The regression analysis indicated that the BMBP existed in the FM- and FFSTM-BM relationships regardless of region and whole body. For the whole body, BMBP was 81.8 kg for FM and 82.2 kg for FFSTM. In regional FM-BM relationships, BMBP was 80.5 kg for arms, 82.6 kg for trunk, and 63.3 kg for legs, and the regression slopes above the BMBP became higher than those below the BP, and vice versa in regional FFSTM-BM relationships (BMBP 104.6 kg for arms, 80.9 kg for trunk, and 79.0 kg for legs). The relative differences in the slopes between below and above BMBP in the regional FM-BM relationships were higher in the arms and trunk than in the legs, and those in the regional FFSTM-BM relationships in the legs than in the trunk. CONCLUSION: Whole-body and regional FM- and FFSTM-BM relationships for male athletes have breakpoints at which the proportion of the tissue masses to BM alters. The BMBP and differences in the distribution of regional FM and FFSTM around the breakpoint are region specific.

Body shape indices are predictors for estimating fat-free mass in male athletes.

It is unknown whether body size and body shape parameters can be predictors for estimating whole body fat-free mass (FFM) in male athletes. This study aimed to investigate whether body size and shape variables can be predictors for FFM in male athletes. Using a whole-body dual-energy X-ray absorptiometry scanner, whole body fat mass (FM) and FFM were determined in 132 male athletes and 14 sedentary males. The sample was divided into two groups: validation (N = 98) and cross-validation (N = 48) groups. Body height (BH), body mass (BM), and waist circumference at immediately above the iliac crest (W) were measured. BM-to-W and W-to-BH ratios were calculated as indices of body shapes. Stepwise multiple regression analysis revealed that BM/W and W/BH were selected as explainable variables for predicting FFM. The equation developed in the validation group was FFM (kg) = 0.883 × BM/W (kg/m) + 43.674 × W/BH (cm/cm)- 41.480 [R2 = 0.900, SEE (%SEE) = 2.3 kg (3.8%)], which was validated in the cross-validation group. Thus, the current results demonstrate that an equation using BM/W and W/BH as independent variables is applicable for predicting FFM in male athletes.

Effect of glutamine supplementation on neutrophil function in male judoists.

Glutamine is an important amino acid for immune function. Though high intensity and prolonged exercise decreases plasma glutamine concentration and causes immune suppression, the relationship between neutrophil functions and glutamine has not yet been found. The purpose of this study was to investigate the impacts of glutamine supplementation on neutrophil function. Twenty-six male university judoists were recruited. Subjects were classified into glutamine and control groups. The glutamine group ingested 3000 mg of glutamine per day and the control group ingested placebo for 2 weeks. Examinations were performed at the start of preunified loading exercise (pre-ULE), then 1 and 2 weeks after ULE (post-ULE). Reactive oxygen species (ROS) production, phagocytic activity, serum opsonic activity and serum myogenic enzymes were measured. Differences between the levels obtained in pre-ULE and post-ULE for the two groups were compared. In the glutamine group, ROS production activity increased 1 week after ULE, whereas it was not observed in the control group (P < 0.001). Though myogenic enzymes increased significantly after ULE (P < 0.001), the glutamine group remained unchanged by supplementation during ULE. Glutamine supplementation has prevented excessive muscle damage and suppression of neutrophil function, especially in ROS production activity, even during an intensive training period.

Effects of soccer matches on neutrophil and lymphocyte functions in female university soccer players.

In this study, changes in physical fatigue and biological functions of Japanese female soccer players were investigated by determining changes in neutrophil and lymphocyte functions. Study subjects included 18 female soccer players. Body composition, serum myogenic enzymes, neutrophil function, including reactive oxygen species (ROS) production capability, phagocytic activity (PA) and serum opsonic activity, as well as lymphocyte subpopulation were measured before and after a soccer match. Levels of myogenic enzymes (AST, ALT, CK and LDH) and immunoglobulins (IgG and IgA) and complements (C3) increased significantly after the match. In addition, leukocyte, neutrophils and lymphocyte counts increased whereas total PA decreased significantly. The number of T and Th1 cells (subsets of T helper cells) decreased whereas Th2 increased significantly. In addition, the number of B cells increased and NK cells decreased significantly after the match. The match was found to result in degenerative changes in and damage to athlete muscle tissues together with damage- and change-mediated stress. These data also suggest a post-match accelerated inflammatory reaction and potential immunosuppression as indicated by reductions in neutrophil PA and lymphocyte functions.